Estimating Young’s modulus of graphene with Raman scattering enhanced by micrometer tip

We demonstrate that the Raman intensities of G and 2D bands of a suspended graphene can be enhanced using a gold tip with an apex size of 2.3 μ m. The enhancement decays with the tip-graphene distance exponentially and remains detectable at a distance of 1.5 μ m. Raman mappings show that the enhanced area is comparable to the apex size. Application of a bias voltage to the tip can attract the graphene so that Raman signals are intensified. The exponential enhancement-distance relationship enables the measurement of the graphene deformation, and the Young’s modulus of graphene is estimated to be 1.48 TPa.

Shao-Wei Weng, Wei-Hsiang Lin, Wei-Bin Su, En-Te Hwu, Peilin Chen, Tsong-Ru Tsai and Chia-Seng Chang

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